Fix empty data mask detection

The ScanFilter class also denotes no-op data masks as a single 0 byte.
Update the MSFT Advertisement Monitor creation logic to handle this
case.

Bug: 360391998
Bug: 365787977
Flag: com.android.bluetooth.flags.le_scan_msft_support
Test: atest BluetoothInstrumentationTests:ScanManagerTest
Change-Id: Icb36acf9c050b95097da6d846e264161e2a97c6a